C++ 读取的dxf文件并用OpenCV绘制出来

先拷贝一小段别人写的开头

注意，以下方法都不用，

“dxflib实现了dxf文件的解析。所有的图元解析完后，都会通过DL_CreationAdapter的虚函数接口回调，所以我们要继承这个类，重写那些想绘制的图元的方法，比如直线对应的就是virtual void addLine(const DL_LineData&); 这个DL_LineData结构体数据保存的就是我们要绘制直线的数据。
绘制我用的是MFC的CDC，双缓冲机制。先把根据数据把所有的图元绘制到内存缓冲中，再一次拷到窗口DC中。值得注意是平移和放大以及坐标系转换。因为应用程序的左上角是原点(0,0)，面我们需要显示给人看的是Y轴正方向是屏幕由下往上。（屏幕实际Y方向是由上往下）。只实现了点，直线，圆，圆弧，多边形，样条曲线（包括用控制点，和顶点两种），以及单行文本。 像线型，线条颜色，多行文本，椭圆这些都是没有实现。但是DXFLIB这些信息有解析出来，只需要按照规则理论上都是可以实现的。”（上面两段是拷贝）

正文开始，C++注释很详细，只写了识别块的单层嵌套，只要了解一些DXF文件格式，就可以根据这个例子修改，可以读出线、圆、等等，直接贴源码
稍后会把整个工程上传，里面包含测试文件等等

1、读线，包括块中的线

void DXFRead::ReadLine(CADDATA &data)
{

FILE *fp = fopen(FILENAME, "r");
if (!fp)
{
cout << "读取" << FILENAME << "失败，任意键退出" << endl;
getchar();
exit(0);
}
else
{
cout << "打开" << FILENAME << "成功，正在读取LINE..." << endl;
}
while (!feof(fp) && !ferror(fp))
{
fscanf(fp, "%s", &str);
//扫描块中线
if (strcmp(str, "BLOCK") == 0)
{
fscanf(fp, "%s", &str);
while (strcmp(str, "2") != 0)
{
fscanf(fp, "%s", &str);
}
//获得块名字
fscanf(fp, "%s", &name);
//如果不是这两个块，做记录
if (strcmp(name,"$MODEL_SPACE") != 0
&& strcmp(name, "$PAPER_SPACE") != 0)
{
while (strcmp(str, "ENDBLK") != 0)
{
fscanf(fp, "%s", &str);
//扫描块中线
if (strcmp(str, "LINE") == 0)
{
//归属块
strcpy(tempLine.name, name);
//x1
while (strcmp(str, "10") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.x1 = atof(str);

//y1
while (strcmp(str, "20") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.y1 = atof(str);

//z1
while (strcmp(str, "30") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.z1 = atof(str);

//x2
while (strcmp(str, "11") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.x2 = atof(str);

//y2
while (strcmp(str, "21") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.y2 = atof(str);

//z2
while (strcmp(str, "31") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tem
d3b3
pLine.z2 = atof(str);

data.LINE.Add(new LINEPoint(tempLine));
}
}
}

}
//扫描主坐标系线
else if (strcmp(str, "LINE") == 0)
{
//归属块
strcpy(tempLine.name, "ReferenceBlock");
//x1
while (strcmp(str, "10") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.x1 = atof(str);

//y1
while (strcmp(str, "20") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.y1 = atof(str);

//z1
while (strcmp(str, "30") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.z1 = atof(str);

//x2
while (strcmp(str, "11") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.x2 = atof(str);

//y2
while (strcmp(str, "21") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.y2 = atof(str);

//z2
while (strcmp(str, "31") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempLine.z2 = atof(str);

data.LINE.Add(new LINEPoint(tempLine));
}
}
cout << "LINE读取完毕..." << endl;
fclose(fp);
}

2、读块的插入信息

void DXFRead::ReadInsert(CADDATA &data)
{
FILE *fp = fopen(FILENAME, "r");
fp = fopen(FILENAME, "r");
if (!fp)
{
cout << "读取" << FILENAME << "失败，任意键退出" << endl;
getchar();
exit(0);
}
else
{
cout << "打开" << FILENAME << "成功，正在读取BLOCK插入信息..." << endl;
}
while (!feof(fp) && !ferror(fp))
{
fscanf(fp, "%s", &str);
if (strcmp(str, "INSERT") == 0)
{
//读取插入块名字
while (strcmp(str, "2") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
strcpy(tempBlock.name, str);

//基点坐标
//rx
while (strcmp(str, "10") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.rx = atof(str);

//ry
while (strcmp(str, "20") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.ry = atof(str);

//rz
while (strcmp(str, "30") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.rz = atof(str);

//读取比例因子
//cx
while (strcmp(str, "41") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.cx = atof(str);

//cy
while (strcmp(str, "42") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.cy = atof(str);

//cz
while (strcmp(str, "43") != 0)
{
fscanf(fp, "%s", &str);
}
fscanf(fp, "%s", &str);
tempBlock.cz = atof(str);

data.BLOCK.Add(new BLOCKPoint(tempBlock));
}
}
cout << "BLOCK插入信息读取完毕..." << endl;
fclose(fp);
}

3、绘图

void DXFRead::DrawImage(CADDATA &data)
{
LINEPoint *linep = NULL;
BLOCKPoint *blockp = NULL;
uchar* Img = NULL;
cout << "开始绘图..." << endl;

//创建图像，深度为8，3通道RGB图像
cvImg = cvCreateImage(cvSize(15000, 15000), 8, 3);
Img = (uchar *)cvImg->imageData;

int step = cvImg->widthStep / sizeof(uchar);
int channels = cvImg->nChannels;
//清空图像
for (int i = 0; i<cvImg->height; i++)
for (int j = 0; j<cvImg->width; j++) {
Img[i*step + j*channels + 0] = 0;
Img[i*step + j*channels + 1] = 0;
Img[i*step + j*channels + 2] = 0;
}
for (int i = 0; i < data.LINE.GetCount(); i++)
{
linep = (LINEPoint*)data.LINE.GetAt(i);
//如果是正常线
if (strcmp(linep->m_line.name, "ReferenceBlock") == 0 )
{
cvLine(cvImg,
cvPoint(20 * ((linep->m_line.x1) + 300), 20 * ((linep->m_line.y1) + 300)),
cvPoint(20 * ((linep->m_line.x2) + 300), 20 * ((linep->m_line.y2) + 300)),
CV_RGB(0, 255, 0), 4);
}
else
{
for (int j = 0; j < data.BLOCK.GetCount(); j++)
{
//获取线归属块信息
blockp = (BLOCKPoint*)data.BLOCK.GetAt(j);
if (strcmp(linep->m_line.name, blockp->m_block.name) == 0)
{
cvLine(cvImg,
cvPoint(20 * ( (blockp->m_block.cx) *(linep->m_line.x1) + blockp->m_block.rx + 300), 20 * ((blockp->m_block.cy) *(linep->m_line.y1) + blockp->m_block.ry + 300  )  ),
cvPoint(20 * ((blockp->m_block.cx) *(linep->m_line.x2) + blockp->m_block.rx + 300), 20 * ( (blockp->m_block.cy) *(linep->m_line.y2) + blockp->m_block.ry + 300  )  ),
CV_RGB(0, 255, 0), 4);
}
}
}

}
cvSaveImage(SAVENAME, cvImg);
//释放图像所占的内存
cvReleaseImage(&cvImg);
}

转载请声明出处

作者：shaynerain

出处：http://blog.csdn.net/shaynerain/article/details/52670536

工程下载：http://download.csdn.net/detail/shaynerain/9704664

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